Image forming system including a plurality of image forming apparatuses, each storing information indicating a plurality of storage locations

ABSTRACT

An image forming system includes a transmitter apparatus that transmits, to a predetermined storage location of multiple storage locations, identification information identifying a user and image data associated with the identification information, and multiple image forming apparatuses. Each of the image forming apparatuses includes a first storage unit that stores storage information indicating the storage locations, a storage location that is included in the storage locations and stores the identification information and the image data associated with the identification information, a retrieval unit that accesses the storage locations, indicated by the storage information stored on the first storage unit, when the identification information is inputted by the user, and retrieves the image data from the storage location, and an image forming unit that forms an image corresponding to the image data retrieved by the retrieval unit.

CROSS-REFERENCE TO RELATE APPLICATIONS

This application is based on and claims priority under 35 USC 119 fromJapanese Patent Application No. 2011-132472 filed Jun. 14, 2011.

BACKGROUND

(i) Technical Field

The present invention relates to an image forming system, an imageforming apparatus, and a computer readable medium storing a programcausing a computer to execute a process for forming an image.

(ii) Related Art

According to one related art technique, a print server apparatus storesimage data specified by a user, and then allows multiple image formingapparatuses to access the image data.

SUMMARY

According to an aspect of the invention, there is provided an imageforming system. The image forming system includes a transmitterapparatus that transmits, to a predetermined storage location ofmultiple storage locations, identification information identifying auser and image data associated with the identification information, andmultiple image forming apparatuses. Each of the image formingapparatuses includes a first storage unit that stores storageinformation indicating the storage locations, a storage location that isincluded in the storage locations and stores the identificationinformation and the image data associated with the identificationinformation, the identification information and the image data beingtransmitted from the transmitter apparatus, a retrieval unit thataccesses the storage locations, indicated by the storage informationstored in the first storage unit, when the identification information isinputted by the user, and retrieves the image data from the storagelocation, and an image forming unit that forms an image corresponding tothe image data retrieved by the retrieval unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present invention will be described indetail based on the following figures, wherein:

FIG. 1 diagrammatically illustrates a configuration of an image formingsystem;

FIG. 2 illustrates a hardware configuration of a client apparatus;

FIG. 3 illustrates a hardware configuration of an image formingapparatus;

FIG. 4 illustrates an example of authentication information;

FIG. 5 illustrates an example of a spooler list;

FIG. 6 is a functional block diagram of the image forming system;

FIG. 7 is a sequence chart illustrating an operation of the imageforming system;

FIG. 8 illustrates a list of print data of the exemplary embodiment;

FIGS. 9A and 9B illustrate an example of the print data of amodification of the exemplary embodiment;

FIG. 10 illustrates an example of history information of themodification;

FIG. 11 illustrates an example of a retrieval ratio of the modification;and

FIG. 12 illustrates a list of the print data of the modification.

DETAILED DESCRIPTION

FIG. 1 diagrammatically illustrates an image forming system 1 of anexemplary embodiment of the present invention. The image forming system1 includes client apparatus 20 (an example of a transmitter apparatus),and image forming apparatuses 30A, 30B, 30C, and 30D. Each of the imageforming apparatuses 30A, 30B, 30C, and 30D is referred to as an imageforming apparatus 30 without the suffix A, B, C, or D if it is notnecessary to discriminate one from another among the image formingapparatuses 30A, 30B, 30C, and 30D. The client apparatus 20 transmitsthe print data to the image forming apparatus 30. The image formingapparatus 30 is an electrophotographic printer, for example. The imageforming apparatus 30 includes a storage location storing the print datareceived from the client apparatus 20.

FIG. 2 illustrates a hardware configuration of the client apparatus 20.The client apparatus 20 includes CPU 21, memory 22, communication unit23, storage unit 24, operation unit 25, and display unit 26. The CPU 21executes a program stored on the memory 22, thereby controlling each ofthe elements of the client apparatus 20. The communication unit 23 is acommunication interface connected to a communication line 2. The CPU 21communicates with the image forming apparatus 30 via the communicationunit 23. The storage unit 24 may be a hard disk. The storage unit 24stores a printer driver 42. The printer driver 42 is a programcontrolling the image forming apparatus 30. The operation unit 25includes a keyboard and a mouse, for example. The operation unit 25 isused to operate the client apparatus 20. The display unit 26 displays animage corresponding to image data.

A user ID and spooler information are beforehand set in the printerdriver 42. The user ID is identification information identifying theuser. The spooler information indicates a storage location where theprint data received from the client apparatus 20 is stored. The spoolerinformation indicates a storage location of one of the image formingapparatuses 30A, 30B, 30C, and 30D. For example, the spooler informationmay be an Internet protocol (IP) address assigned to the image formingapparatus 30 or a name of the image forming apparatus 30. User ID“user001” and spooler information “spoolerC” indicative of the storagelocation of the image forming apparatus 30C are set in the printerdriver 42. The spooler information set in the printer driver 42 may bemodified by the user.

FIG. 3 illustrates a hardware configuration of the image formingapparatus 30. The image forming apparatus 30 includes controller 31,communication unit 32, storage unit 33, user interface (UI) unit 34,image forming unit 35, and card reading unit 36. The controller 31includes CPU 37, and memory 38. The CPU 37 executes a program stored onthe memory 38, thereby controlling each of the elements of the imageforming apparatus 30. The communication unit 32 is a communicationinterface connected to the communication line 2. The controller 31communicates with one of the client apparatus 20, and another imageforming apparatus 30 via the communication unit 32. The storage unit 33(an example of a first storage unit) may be a hard disk. The storageunit 33 stores the print data received from the client apparatus 20. Thestorage unit 33 also stores authentication information 41 and a spoolerlist 43 (an example of storage information).

FIG. 4 illustrates an example of the authentication information 41. Theauthentication information 41 includes a user ID and a password. Theuser ID is identification information identifying the user. The passwordis used to verify that the user is an authorized user. The password isset up by the user.

FIG. 5 illustrates an example of the spooler list 43. The spooler list43 lists the spooler information indicating the storage locations of theimage forming apparatuses 30 included in the image forming system 1. Asdescribed above, the image forming system 1 includes the image formingapparatuses 30A, 30B, 30C, and 30D. The spooler list 43 of FIG. 5 thuslists spooler information “spoolerA” indicating a storage location ofthe image forming apparatus 30A, spooler information “spoolerB”indicating a storage location of the image forming apparatus 30B,spooler information “spoolerC” indicating a storage location of theimage forming apparatus 30C, and spooler information “spoolerD”indicating a storage location of the image forming apparatus 30D.

The UI unit 34 of FIG. 3 includes a touchscreen and keys. The UI unit 34is used to operate the image forming apparatus 30. The image formingunit 35 forms on paper an image corresponding to the image data. Thecard reading unit 36 reads information, stored on an integrated circuit(IC) card, in a contactless fashion. The IC card is beforehand suppliedto the user to authenticate the user. The IC card stores the user ID“user001” and password “1234” of the user included in the authenticationinformation 41.

FIG. 6 is a functional block diagram of the image forming system 1. Inthe image forming system 1, one image forming apparatus 30 is identicalin function to another image forming apparatus 30. A storage location101 is arranged in the storage unit 33. A retrieval unit 102 isimplemented when the CPU 37 executes the program. The client apparatus20 transmits the user ID identifying the user and the image dataassociated with the user ID to a predetermined storage location 101 outof multiple storage locations 101. The storage location 101 stores in anassociated state the user ID and the image data received from the clientapparatus 20. When the user enters the user ID using the card readingunit 36, the retrieval unit 102 accesses multiple storage locationsindicated by the spooler list 43 stored on the storage unit 33, andretrieves the image data from the storage location storing the imagedata associated with the input user ID. The image forming unit 35 formsan image corresponding to the image data retrieved by the retrieval unit102.

FIG. 7 is a sequence chart of the operation of the image forming system1. The user specifies the image data using the operation unit 25 in theclient apparatus 20 and issues an image forming instruction of the imagedata. The CPU 21 executes the printer driver 42, thereby generating theprint data including the image data specified by the user and the userID of the user. The user may specify image data D1 here. As describedabove, the user ID “user001” of the user is set in the printer driver42. The print data thus includes the user ID “user001” and the imagedata D1.

Upon generating the print data, the CPU 21 transmits the generated printdata to the storage location set in the printer driver 42 via thecommunication unit 23 (step S11). As described above, the spoolerinformation “spoolerC” is set in the printer driver 42. The print datais thus transmitted to the image forming apparatus 30C.

A controller 31C in the image forming apparatus 30C receives the printdata from the client apparatus 20 via a communication unit 32C. Uponreceiving the print data, the controller 31C causes a storage unit 33Cto store the received print data (step S12). In this process, the printdata including the image data D1 and the user ID “user001” is receivedfrom the client apparatus 20. The storage unit 33C stores the print dataincluding the image data D1 and the user ID “user001.” In the storageoperation, the storage unit 33C associates the image data D1 with theuser ID “user001.”

After providing an image forming instruction on the client apparatus 20,the user moves to a place where one of the image forming apparatuses30A, 30B, 30C, and 30D is installed. For example, the user may move tothe place where the image forming apparatus 30 usually used by the useris installed. If the image forming apparatus 30 usually used by the useris currently used by someone else, the user may move to another imageforming apparatus 30 nearby. The user may move to an image formingapparatus 30 closest to them. In other words, the user moves to a placeto use one of the image forming apparatuses 30A, 30B, 30C, and 30D. Theuser may now move to the image forming apparatus 30D.

The UI unit 34 in the image forming apparatus 30 presents anauthentication screen. The image forming apparatus 30 receives no inputfrom the user if the user is not authenticated. The user moves to theimage forming apparatus 30D and swipes their IC card over the cardreading unit 36D for authentication. If the IC card is positioned closeto the card reading unit 36D, the card reading unit 36D reads the userID and the password stored on the IC card (step S13). Upon reading thesepieces of information from the IC card, the card reading unit 36D inputsthe read information to the controller 31D. As described above, the ICcard stores the user ID “user001” and the password “1234.” The user ID“user001” and the password “1234” are input to the controller 31B.

If the user ID and the password are input, the controller 31D checks theinput user ID and password against the user ID and password included inthe authentication information 41 stored on the storage unit 33D. Thecontroller 31D thus determines whether a user of the image formingapparatus 30D is an authorized user (step S14). If the input user ID andpassword are not included in the authentication information 41, thecontroller 31D determines that the user of the image forming apparatus30D is not an authorized user (no loop from step S14). The controller31D causes the UI unit 34D to display a message to the effect thatauthentication is unsuccessful, and ends the process. As illustrated inFIG. 4, the input user ID “user001” and password “1234” are included inthe authentication information 41. In such a case, the controller 31Ddetermines that the user of the image forming apparatus 30D is anauthorized user (yes loop from step S14).

If the user of the image forming apparatus 300 is an authorized user,the controller 31D accesses all the storage locations indicated by thespooler information of the spooler list 43 stored on the storage unit33D, and retrieves the print data including the user ID of the user(step S15). The spooler list 43 of FIG. 5 lists spooler information“spoolerA,” “spoolerB,” “spoolerC,” and “spoolerD.” The controller 31Dthus accesses the image forming apparatuses 30A, 30B, and 30C and thestorage unit 33D of the host image forming apparatus 30D. Morespecifically, the controller 31D accesses the storage unit 33D anddetermines whether the print data including the user ID “user001” isstored on the storage unit 33D. If the print data is stored on thestorage unit 33D, the controller 31D reads all the print data from thestorage unit 33D. The controller 31D notifies the image formingapparatuses 30A, 30B, and 30C of the user ID “user001” via thecommunication unit 32D, and requests the image forming apparatuses 30A,30B, and 30C to transmit the print data including that user ID. Inresponse, the image forming apparatuses 30A, 30B, and 30C transmit theprint data including the user ID to the image forming apparatus 30D.More specifically, a controller 31A in the image forming apparatus 30Adetermines whether the print data including the user ID is stored on astorage unit 33A. If the user ID is stored on the storage unit 33A, thecontroller 31A reads all the print data from the storage unit 33A. Thecontroller 31A transmits the read print data to the image formingapparatus 300 via a communication unit 32A. The image formingapparatuses 30B and 30C operate in a similar fashion. In theabove-described step S12, the print data including the user ID “user001”and the image data D1 is stored on a storage unit 33C. The print data isthus transmitted from the image forming apparatus 30C. The controller31D in the image forming apparatus 30D receives the print data via thecommunication unit 32D if the print data is transmitted from the imageforming apparatus 30C.

Upon receiving the print data, the controller 310 causes the UI unit 34Dto display a list of the retrieved print data (step S16). FIG. 8illustrates the list of the print data displayed on the UI unit 34D.Displayed in the list of the print data is identification informationidentifying the print data retrieved in step S15. The list of the printdata of FIG. 8 includes the user ID “user001” and the file name of theimage data D1 included in the print data retrieved from the imageforming apparatus 30C. Using the UI unit 34D, the user selects printdata from the list of the print data and presses a “PRINT” button 51. Ifthe “PRINT” button 51 is pressed, the controller 31D extracts the imagedata from the selected print data, and causes the image forming unit 35Dto form an image corresponding to the extracted image data (step S17). Aregion displaying the user ID “user001” and the file name of the imagedata D1 may be selected and the “PRINT” button 51 may be pressed in thelist of the print data of FIG. 8. The controller 31D extracts the imagedata D1 from the print data received from the image forming apparatus30C. The image forming unit 35D outputs an image corresponding to theextracted image data D1 by forming the image on a paper sheet.

In the exemplary embodiment, the image corresponding to the image datamay be formed using any of the image forming apparatuses 30 if each ofthe image forming apparatuses 30 has the storage location storing theimage data.

The present invention is not limited to the exemplary embodimentdescribed above. The exemplary embodiment may be modified as describedbelow and resulting modifications may be combined.

First Modification

In the above-described step S15, the controller 31D may access first thestorage unit 33D (an example of an internal storage location) in thehost apparatus, and may then access the storage location (an example ofan external storage location) of each of the other image formingapparatuses 30A, 30B, and 30C via the communication unit 32D. It isassumed herein that the storage unit 33C in the image forming apparatus30C stores first print data including the user ID “user001” and theimage data D1 and that the storage unit 33D stores second print dataincluding the user ID “user001” and image data D2. The controller 31Daccesses first the storage unit 330 to retrieve the second print data.Upon retrieving the second print data, the controller 310 (an example ofa display controller) causes the UI unit 34D (an example of a displayunit) to display a list of the print data corresponding to the secondprint data. FIG. 9A illustrates an example of the list of the print datadisplayed on the UI unit 340. The list of the print data lists the userID “user001” and the file name of the image data D2 included in thesecond print data. When the list of the print data is displayed, theuser may select the second print data and press the “PRINT” button 51.

The controller 31D accesses the storage unit 330 and then accesses theimage forming apparatuses 30A, 30B, and 30C via the communication unit32D. The controller 310 thus retrieves the first print data from theimage forming apparatus 30C. Upon retrieving the first print data, thecontroller 31D adds the identification information of the retrievedfirst print data to the list of the print data displayed on the UI unit34D. FIG. 9B illustrates an example of the resulting list of the printdata displayed on the UI unit 34D. The list of the print data lists, inaddition to the identification information of the second print dataillustrated on FIG. 9A, the user ID “user001” and the file name of theimage data D1 included in the first print data. The list of the printdata typically lists the identification information of the print dataretrieved from the storage unit 33D on the top thereof. Theidentification information of the first print data is displayed belowthe identification information of the second print data on the list. Inthe list of the print data of the modification, the identificationinformation of the print data retrieved from the storage unit 33D isdisplayed at a predetermined position. The position is not limited tothe top of the list on the UI unit 34D. The position may be at thecenter position on the list. The position may be easily selectable bythe user.

According to the modification, the print data stored on the hostapparatus may be retrieved fast. When the list the print data of FIG. 9Ais displayed, the selection of the print data retrieved from the storagelocation within the host apparatus is accepted, and the image forming isinitiated. Since the identification information of the print dataretrieved from the storage location within the host apparatus istypically displayed at the predetermined position, the user may selectthat print data with ease. Although the first print data and the secondprint data are retrieved from the different storage locations, theidentification information of the first print data and theidentification information of the second print data are displayed withone piece next to the other on the list as illustrated in FIG. 9B. Thisarrangement may give an impression that the first print data and thesecond print data are stored on the same storage location.

Second Modification

As described above, the spooler information indicating the storagelocation of the print data is set beforehand in the printer driver 42 ofthe client apparatus 20. The print data transmitted from the same clientapparatus 20 is stored on the same storage location each time if thespooler information is not modified. In step S15, the controller 31D mayaccess the storage location in the order of from high to low retrievalfrequency of the print data of the user.

The storage unit 33D (an example of a second storage unit) storeshistory information 44. The history information 44 indicates on a peruser basis a history of the storage location from which the print datais retrieved. FIG. 10 illustrates an example of the history information44. The history information 44 related to past operations of the imageforming apparatus 30D lists, in an associated state, retrieval time ofthe print data, a user ID inputted by the user, and the spoolerinformation indicating the storage location from which the print data isretrieved. When the user ID is input in step S13, the controller 31Dextracts history information 44 including the user ID from the historyinformation 44 stored on the storage unit 33D. For example, if the userID “user001” is input, the controller 31D extracts the historyinformation 44 including the user ID “user001” from the historyinformation 44 of FIG. 10.

In response to the extracted history information 44, the controller 31D(an example of a calculator unit) calculates a retrieval ratio (anexample of a retrieval frequency) at which the print data is retrievedfrom the storage location of the image forming apparatus 30. Forexample, the print data of the user having the user ID “user001” may beretrieved by 100 times, and out of 100 times, the number of times atwhich the print data may be retrieved from the storage location of theimage forming apparatus 30C may be 90 times. In this case, the extractedhistory information 44 includes 100 pieces of spooler information andout of 100 pieces, 90 pieces of spooler information is “spoolerC.” Theretrieval ratio of the storage location of the image forming apparatus30C is 90/100×100=90%. The retrieval ratio of another storage locationis also calculated in a similar fashion. If the retrieval ratio of thestorage location is calculated, the controller 31D causes the storageunit 33D to store, in an associated state, the calculated retrievalratio of the storage location and the spooler information indicating thestorage location. The retrieval ratio is thus stored on the storage unit33D as illustrated in FIG. 11.

Upon calculating the retrieval ratio, the controller 31D accesses thestorage locations in the order from high to low retrieval ratio in stepS15. As illustrated in FIG. 11, the retrieval ratio of the storagelocation of the image forming apparatus 30A is “2%,” the retrieval ratioof the storage location of the image forming apparatus 30B is “0%,” theretrieval ratio of the storage location of the image forming apparatus30C is “90%,” and the retrieval ratio of the storage location of theimage forming apparatus 30D is “8%.” In this case, the controller 31Daccesses the storage location of the image forming apparatus 30C havingthe highest retrieval ratio, then accesses the storage location theimage forming apparatus 30D having the second highest retrieval ratio,then accesses the storage location of the image forming apparatus 30Ahaving the third highest retrieval ratio, and finally accesses thestorage location of the image forming apparatus 30B having the lowestretrieval ratio. The print data are retrieved fast from the storagelocations in the order of from high low retrieval ratio.

If the print data are retrieved from multiple storage locations in stepS15, the controller 31D (an example of a display controller) may arrangeand display the identification information of the print data in theorder of from high low calculated retrieval ratio in step S16. It isherein assumed in step S15 that first print data including the user ID“user001” and the image data D1 are retrieved from the storage locationof the image forming apparatus 30C, that second print data including theuser ID “user001” and image data D2 are then retrieved from the storagelocation of the image forming apparatus 30D, and that third print dataincluding the user ID “user001” and the image data D3 are retrieved fromthe storage location of the image forming apparatus 30A. In the exampleof FIG. 11, the retrieval ratio of the storage location of the imageforming apparatus 30A is “2%,” the retrieval ratio of the storagelocation of the image forming apparatus 30C is “90%,” and the retrievalratio of the storage location of the image forming apparatus 30D is“8%.” As illustrated in FIG. 12, the controller 31D causes the UI unit34 to display, on the top of the list the print data, the identificationinformation (the user ID “user001” and the file name of the image dataD1) of the first print data retrieved from the storage location of theimage forming apparatus 30C having the highest retrieval ratio. The UIunit 34 then displays on the second position of the list theidentification information (the user ID “user001” and the file name ofthe image data D1) of the second print data retrieved from the storagelocation of the image forming apparatus 30D having the second highestretrieval ratio. The UI unit 34 then displays on the third position ofthe list the identification information (the user ID “user001” and thefile name of the image data D3) of the third print data retrieved fromthe storage location of the image forming apparatus 30A having the thirdhighest retrieval ratio. With ease, the user may select the print dataretrieved from the storage location having the high retrieval ratio.

Third Modification

A new image forming apparatus 30E may be connected to the communicationline 2. The image forming apparatuses 30A, 30B, 30C, and 30D may thendetect that the new image forming apparatus 30E has been connected, andmay add to the spooler list 43 the storage information indicating thestorage location of the image forming apparatus 30E. More specifically,the controller 31A detects via the communication unit 32A that the newimage forming apparatus 30E is connected. Upon detecting the connectionof the new image forming apparatus 30E, the controller 31A requests thenew image forming apparatus 30E via the communication unit 32A totransmit the spooler information. The image forming apparatuses 30B,30C, and 30D perform a similar operation. In response to the request, acontroller 31E in the image forming apparatus 30E transmits to the imageforming apparatuses 30A, 30B, 30C, and 30D the spooler informationindicating the storage location of the image forming apparatus 30E via acommunication unit 32E. The spooler information is thus transmitted fromthe image forming apparatus 30E. The controller 31A receives the spoolerinformation via the communication unit 32A. The controller 31A thus addsthe received spooler information to the spooler list 43 stored on thestorage unit 33A. More specifically, the controller 31A (an example of astorage controller) causes the storage unit 33A to store the spoolerinformation retrieved from the image forming apparatus 30E. The imageforming apparatuses 30B, 30C, and 30D perform a similar operation. Theprint data of the user is thus retrieved from the storage location ofthe image forming apparatus 30E.

The controller 31E also requests the image forming apparatuses 30A, 308,30C, and 30D via the communication unit 32E to transmit the spoolerinformation. In response to the request, the controller 31A transmits tothe image forming apparatus 30E the spooler information indicating thestorage location of the image forming apparatus 30A via thecommunication unit 32A. The image forming apparatuses 308, 30C, and 30Dperform a similar operation. The controller 31E receives via thecommunication unit 32E the spooler information from the image formingapparatuses 30A, 30B, 30C, and 30D. The controller 31E generates thespooler list 43 using the received spooler information, and causes thestorage unit 33E to store the spooler list 43. Alternatively, thecontroller 31E may request one of the image forming apparatuses 30A,30B, 30C, and 30D to transmit the spooler list 43 via the communicationunit 32E, receive the spooler list 43 transmitted in response to therequest, and cause the storage unit 33E to store the spooler list 43.The image forming apparatus 30E may retrieve the print data of the userfrom the storage locations of the image forming apparatuses 30A, 30B,30C, and 30D newly connected thereto via the communication line 2.

Fourth Modification

The image forming apparatus 30 may be disconnected from thecommunication line 2 for repair or dismounting. Another image formingapparatus 30 may detect the image forming apparatus 30 disconnected fromthe communication line 2 and may delete from the spooler list 43 thespooler information of the detected image forming apparatus 30. Morespecifically, the controller 31 periodically transmits to another imageforming apparatus 30 via the communication unit 32 information verifyingthat the other image forming apparatus 30 is accessible. If the otherimage forming apparatus 30 replies, the controller 31 determines thatthe other image forming apparatus 30 remains connected to thecommunication line 2. For example, if no reply is received from theother image forming apparatus 30A, the image forming apparatus 30A maybe disconnected from the communication line 2 or may be powered off. Theimage forming apparatuses 30B, 30C, and 30D determine whether the imageforming apparatus 30A is disconnected from the communication line 2.More specifically, at predetermined time intervals, the controller 31Btransmits to the image forming apparatus 30A via the communication unit32B information verifying that the image forming apparatus 30A isaccessible. This operation is consecutively repeated by a predeterminednumber of times. If no reply is received at each time, the controller31B determines that the image forming apparatus 30A is disconnected fromthe communication line 2. The controller 31B (an example of a detectorunit) thus detects the image forming apparatus 30A that is disconnectedfrom the communication line 2. The image forming apparatuses 300 and 30Dperform a similar operation. If the image forming apparatus 30A isdetected as being disconnected from the communication line 2, thecontroller 31B deletes from the spooler list 43 the spooler information“spoolerA” indicating the storage location of the detected image formingapparatus 30A. Once the spooler information “spoolerA” is deleted fromthe spooler list 43, the image forming apparatus 30B does not access theimage forming apparatus 30A. The image forming apparatuses 30C and 30Dperform a similar operation.

If the image forming apparatus 30A is disconnected from thecommunication line 2 for repair, the image forming apparatus 30A may bereconnected to the communication line 2 after being repaired. In such acase, the process discussed with reference to the third modification isperformed, storing the spooler list 43 of FIG. 5 on the storage unit 33Ain the image forming apparatus 30A. The spooler information “spoolerA”indicating the storage location of the image forming apparatus 30A isadded to the spooler list 43 of the image forming apparatuses 30B, 30C,and 30D. With this operation, the print data may be exchanged betweenthe image forming apparatus 30A and each of the image formingapparatuses 30B, 30C, and 30D.

Fifth Modification

In the exemplary embodiment, the spooler information indicating a singlestorage location is set in the printer driver 42. The spoolerinformation indicating multiple storage locations may be set. Forexample, primary spooler information and secondary spooler informationmay be set in the printer driver 42. The primary spooler informationindicates a storage location having the highest priority. The secondaryspooler information indicates a storage location having the secondhighest priority. Primary spooler information “spoolerC” and secondaryspooler information “spoolerD” may now be set in the printer driver 42.Prior to transmitting the print data, the CPU 21 transmits a testmessage to the image forming apparatus 30C indicated by the primaryspooler information “spoolerC” via the communication unit 23. If a replyis received in response to the message from the image forming apparatus30C, the CPU 21 determines that normal communication is established withthe image forming apparatus 30C. The CPU 21 then transmits the printdata to the image forming apparatus 30C via the communication unit 23.If no reply is received from the image forming apparatus 30C within apredetermined period of time, the CPU 21 determines that normalcommunication with the image forming apparatus 30C is difficult. Noreply may be received from the image forming apparatus 30C if a faultoccurs in the image forming apparatus 30C or if a fault occurs in thecommunication line 2 between the client apparatus 20 and the imageforming apparatus 30C. In such a case, the CPU 21 transmits via thecommunication unit 23 a test message to the image forming apparatus 30Dindicated by the secondary spooler information “spoolerD.” If a reply isreceived in response to the message from the image forming apparatus 30Dwithin a predetermined period of time, the CPU 21 transmits the printdata to the image forming apparatus 30D.

Sixth Modification

In the exemplary embodiment, the print data is stored on only one of themultiple storage locations. The same print data may be stored on themultiple storage locations. For example, the client apparatus 20 maytransmit the print data to the multiple storage locations. As describedwith reference to the fifth modification, the primary spoolerinformation “spoolerC” and the secondary spooler information “spoolerD”may now be set in the printer driver 42. When transmitting the printdata to the image forming apparatus 30C, the client apparatus 20 alsotransmits the print data to the image forming apparatus 30D. The printdata of the user may be difficult to retrieve from the image formingapparatus 30C if the image forming apparatus 30C remains powered off.With the print data transmitted to the image forming apparatus 30D,however, the print data may still be retrieved from the image formingapparatus 30D.

The image forming apparatus 30 having received the print data from theclient apparatus 20 may make a copy of the print data and may transmitthe copy to another storage location. In such a case, the storagelocation as a destination of the copy is predetermined. The imageforming apparatus 30D may be set as the storage location of the copydestination in the image forming apparatus 30C. Upon receiving the printdata from the client apparatus 20, the image forming apparatus 30C makesa copy of the print data and transmits the copy to the image formingapparatus 30D. The print data of the user may be difficult to retrievefrom the image forming apparatus 30C if the image forming apparatus 30Cremains powered off. With the copy of the print data transmitted to theimage forming apparatus 30D, however, the print data may still beretrieved from the image forming apparatus 30D.

If the print data is retrieved from the image forming apparatus 30D, theimage forming apparatus 30C may transmit to the image forming apparatus30D information instructing the image forming apparatus 30D to deletethe print data thereon. Upon receiving the information, the controller31D in the image forming apparatus 30D deletes the specified print datafrom the storage unit 33D.

Seventh Modification

In the exemplar embodiment, the image forming apparatus 30 authenticatesthe user. The image forming system 1 may include an authenticationserver apparatus, and the authentication server apparatus mayauthenticate the user. The authentication information 41 is stored on astorage unit of the authentication server apparatus. When the userenters the user ID and password, the controller 31 in the image formingapparatus 30 transmits the input user ID and password to theauthentication server apparatus via the communication unit 32 and thenrequests the authentication server apparatus to authenticate the user.In response to the request, the authentication server apparatus checksthe user ID and password from the image forming apparatus 30 against theuser ID and password included in the authentication information 41stored on the storage unit. The authentication server apparatus thusdetermines whether the user of the image forming apparatus 30 is anauthorized user. If the user of the image forming apparatus 30 is anauthorized user, the authentication server apparatus transmits to theimage forming apparatus 30 information indicating that authentication issuccessful. The controller 31 proceeds to step S15. The controller 31does not need to perform step S14.

Eighth Modification

The number of client apparatuses 20 is not limited to one and the numberof image forming apparatuses 30 is not limited to one. Depending on thenumber of users, the number of client apparatuses 20 and the number ofimage forming apparatuses 30 may be increased, or decreased

Ninth Modification

The authentication of the user may be performed without using the ICcard. For example, the user may enter the user's own ID and passwordusing the UI unit 34 in the image forming apparatus 30. Biometricinformation such as fingerprint may be used in place of the user ID andpassword. In such a case, the image forming apparatus 30 includes adevice reading the biometric information.

Tenth Modification

The image forming apparatus 30 may be a printer that forms an image in amethod other than the electrophotographic method. The image formingapparatus 30 may form a monochrome image or a color image. The imageforming apparatus 30 may have a copying function and/or a scanningfunction.

Eleventh Modification

The program executed by each CPU 21, and CPU 37 may be supplied in arecorded state on a recording medium such as magnetic tape, magneticdisk, flexible disk, optical disk, magneto-optical disk, or memory. Theprogram may be then installed onto one of the client apparatus 20, andthe image forming apparatus 30. The program may be downloaded onto oneof the client apparatus 20, and the image forming apparatus 30 via acommunication line such as the Internet.

Twelfth Modification

In the exemplary embodiment, the list of print data is displayed afterthe print data is retrieved in step S15. The image forming apparatus 30may retrieve only the identification information of the print data priorto the retrieval of the print data, and then may display the list ofprint data. When the user selects the print data from the list of printdata, the image forming apparatus 30 retrieves the selected print datafrom the storage location.

If the print data is retrieved in step S15, the image forming apparatus30 may form an image corresponding to the retrieved print data withoutdisplaying the list of print data. In this case, the user is freed fromselecting the print data.

Thirteenth Modification

In the exemplary embodiment, the spooler information indicating thestorage location of the image forming apparatus 30 included in the imageforming system 1 is written in the spooler list 43. The spoolerinformation may be appropriately set. For example, only the spoolerinformation indicating the storage location of a specific image formingapparatus 30 may be written in the spooler list 43. Alternatively, onlythe spooler information indicating the storage location of an imageforming apparatus 30 belonging to the same sub-net may be written in thespooler list 43. For example, if the image forming apparatuses 30A, 30B,and 300 belong to the same sub-net, the spooler information indicatingthe storage locations of the image forming apparatuses 30A, 30B, and 30Cis written in the spooler list 43. In this case, the storage locationsmay be shared by the image forming apparatuses 30A, 30B, and 30C.

The foregoing description of the exemplary embodiments of the presentinvention has been provided for the purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Obviously, many modificationsand variations will be apparent to practitioners skilled in the art. Theembodiments were chosen and described in order to best explain theprinciples of the invention and its practical applications, therebyenabling others skilled in the art to understand the invention forvarious embodiments and with the various modifications as are suited tothe particular use contemplated. It is intended that the scope of theinvention be defined by the following claims and their equivalents.

What is claimed is:
 1. An image forming system comprising: a transmitterapparatus that transmits, to a predetermined storage location of aplurality of storage locations, identification information identifying auser and image data associated with the identification information; anda plurality of image forming apparatuses, each of the plurality of imageforming apparatuses including: a first storage unit that stores storageinformation indicating the plurality of storage locations; a storagelocation that is included in the plurality of storage locations andstores the identification information and the image data associated withthe identification information, the identification information and theimage data being transmitted from the transmitter apparatus; a retrievalunit that accesses the plurality of storage locations indicated by thestorage information stored in the first storage unit, when theidentification information is inputted by the user, and retrieves theimage data from the storage location; and an image forming unit thatforms an image corresponding to the image data retrieved by theretrieval unit, wherein the transmitter apparatus and the plurality ofimage forming apparatuses are connected via a first communication line,each of the plurality of the image forming apparatuses furthercomprising a storage controller that retrieves, from a second imageforming apparatus which is newly connected to the first communicationline, storage information indicating a storage location of the secondimage forming apparatus when the second image forming apparatus is newlyconnected to the first communication line, and causes the first storageunit to store the retrieved storage information.
 2. The image formingsystem according to claim 1, wherein each of the plurality of imageforming apparatuses further comprises a detector unit that detects athird image forming apparatus that is disconnected from the firstcommunication line, and wherein the storage controller deletes from thefirst storage unit the storage information indicating the storagelocation of the third image forming apparatus that is detected by thedetector unit.
 3. The image forming system according to claim 1, whereinwhen one of the plurality of the image forming apparatuses is connectedto a second communication line, the storage controller of the imageforming apparatus retrieves, from a fourth image forming apparatus whichis connected via the second communication line, the storage informationindicating the storage location of the fourth image forming apparatus,and causes the first storage unit to store the retrieved storageinformation.
 4. The image forming system according to claim 2, whereinwhen one of the plurality of image forming apparatuses is connected to asecond communication line, the storage controller of the image formingapparatus retrieves, from a fourth image forming apparatus connected viathe second communication line, the storage information indicating thestorage location of the fourth image forming apparatus, and causes thefirst storage unit to store the retrieved storage information.
 5. Theimage forming system according to claim 1, wherein each of the pluralityof the image forming apparatuses comprises: a second storage unit thatstores the input identification information and a history of the storagelocation associated with the identification information, the storagelocation from which the retrieval unit retrieves the image data when theidentification information is inputted; and a calculator unit that, whenthe identification is inputted by the user, calculates a retrievalfrequency of retrieving the image data from each of the storagelocations in accordance with the history of the storage locationassociated with the identification information and stored on the secondstorage unit, wherein the retrieval unit accesses the storage locationsin the order of from the high to the low retrieval frequency calculatedby the calculator unit.
 6. The image forming system according to claim5, wherein each of the plurality of the image forming apparatusescomprises a display controller, the display controller causing a displayunit to arrange and display the identification information, when theimage data is retrieved from the plurality of storage locations by theretrieval unit, the identification information identifying the retrievedimage data in the order of from the high to the low retrieval frequencycalculated for the plurality of storage locations by the calculatorunit, and when image data is selected from the retrieved image data bythe user in accordance with the identification information displayed onthe display unit, the image forming unit forms an image corresponding tothe selected image data.
 7. The image forming system according to claim1, wherein each of the plurality of the image forming apparatusescomprises a display controller, wherein when the retrieval unitretrieves first image data from an internal storage location within theimage forming apparatus hosting the retrieval unit and second image datafrom an external storage location within another image formingapparatus, the display controller causes identification informationidentifying the first image data to be displayed at a predeterminedposition on a display unit, and causes identification informationidentifying the second image data to be displayed at a position otherthan the predetermined position on the display unit, and when image datais selected from the retrieved image data by the user in accordance withthe identification information displayed on the display unit, the imageforming unit forms an image corresponding to the selected image data. 8.A plurality of image forming apparatuses, each image forming apparatuscomprising: a first storage unit that stores storage informationindicating a plurality of storage locations; a storage location thatstores identification information identifying a user in accordance withimage data when the identification information and the image data arereceived from a transmitter unit; a retrieval unit that accesses theplurality of storage locations indicated by the storage informationstored on the first storage unit when the identification information isinputted by the user, and retrieves the image data from the storagelocation; and an image forming unit that forms an image corresponding tothe image data retrieved by the retrieval unit, wherein the plurality ofimage forming apparatuses are connected via a first communication line,each of the plurality of the image forming apparatuses furthercomprising a storage controller that retrieves, from a second imageforming apparatus which is newly connected to the first communicationline, storage information indicating a storage location of the secondimage forming apparatus when the second image forming apparatus is newlyconnected to the first communication line, and causes the first storageunit to store the retrieved storage information.
 9. A non-transitorycomputer readable medium storing a program causing a computer to executea process for forming an image, the computer including a storage unitstoring storage information indicating a plurality of storage locations,the process comprising: connecting a plurality of image formingapparatuses via a first communication line, each of the plurality of theimage forming apparatuses comprising a storage controller thatretrieves, from a second image forming apparatus which is newlyconnected to the first communication line, storage informationindicating a storage location of the second image forming apparatus whenthe second image forming apparatus is newly connected to the firstcommunication line, and causes the storage unit to store the retrievedstorage information, storing identification information and image datawith the identification information associated with each other when theidentification information identifying a user and the image data arereceived from a transmitter apparatus; accessing the plurality ofstorage locations indicated by the storage information stored on thestorage unit and retrieving the image data from the storage locationwhen the identification information is inputted by the user; and formingan image corresponding to the retrieved image data.
 10. An image formingsystem comprising: a transmitter apparatus that transmits, to apredetermined storage location of a plurality of storage locations,identification information identifying a user and image data associatedwith the identification information; and a plurality of image formingapparatuses, each of the plurality of image forming apparatusesincluding: a first storage unit that stores storage informationindicating the plurality of storage locations; a storage location thatis included in the plurality of storage locations and stores theidentification information and the image data associated with theidentification information, the identification information and the imagedata being transmitted from the transmitter apparatus; a retrieval unitthat accesses the plurality of storage locations indicated by thestorage information stored in the first storage unit, when theidentification information is inputted by the user, and retrieves theimage data from the storage location; and an image forming unit thatforms an image corresponding to the image data retrieved by theretrieval unit, wherein the transmitter apparatus and the plurality ofimage forming apparatuses are connected via a first communication line,each of the plurality of the image forming apparatuses furthercomprising a storage controller that retrieves, from a second imageforming apparatus which is newly connected to the first communicationline, storage information indicating a storage location of the secondimage forming apparatus when the second image forming apparatus is newlyconnected to the first communication line, and causes the first storageunit to store the retrieved storage information, and wherein each of theplurality of image forming apparatuses further comprises a detector unitthat detects a third image forming apparatus that is disconnected fromthe first communication line, and the storage controller deletes fromthe first storage unit the storage information indicating the storagelocation of the third image forming apparatus that is detected by thedetector unit.
 11. The image forming system according to claim 10,wherein each of the plurality of the image forming apparatuses furthercomprises: a second storage unit that stores the input identificationinformation and a history of the storage location associated with theidentification information, the storage location from which theretrieval unit retrieves the image data when the identificationinformation is inputted; and a calculator unit that, when theidentification is inputted by the user, calculates a retrieval frequencyof retrieving the image data from each of the storage locations inaccordance with the history of the storage location associated with theidentification information and stored on the second storage unit,wherein the retrieval unit accesses the storage locations in the orderof from the high to the low retrieval frequency calculated by thecalculator unit.
 12. The image forming system according to claim 10,wherein each of the plurality of the image forming apparatuses comprisesa display controller, wherein when the retrieval unit retrieves firstimage data from an internal storage location within the image formingapparatus hosting the retrieval unit and second image data from anexternal storage location within another image forming apparatus, thedisplay controller causes identification information identifying thefirst image data to be displayed at a predetermined position on adisplay unit, and causes identification information identifying thesecond image data to be displayed at a position other than thepredetermined position on the display unit, and when image data isselected from the retrieved image data by the user in accordance withthe identification information displayed on the display unit, the imageforming unit forms an image corresponding to the selected image data.13. A plurality of image forming apparatuses, each image formingapparatus comprising: a first storage unit that stores storageinformation indicating a plurality of storage locations; a storagelocation that stores identification information identifying a user inaccordance with image data when the identification information and theimage data are received from a transmitter unit; a retrieval unit thataccesses the plurality of storage locations indicated by the storageinformation stored on the first storage unit when the identificationinformation is inputted by the user, and retrieves the image data fromthe storage location; and an image forming unit that forms an imagecorresponding to the image data retrieved by the retrieval unit, whereinthe plurality of image forming apparatuses are connected via a firstcommunication line, each of the plurality of the image formingapparatuses further comprising a storage controller that retrieves, froma second image forming apparatus which is newly connected to the firstcommunication line, storage information indicating a storage location ofthe second image forming apparatus when the second image formingapparatus is newly connected to the first communication line, and causesthe first storage unit to store the retrieved storage information,wherein each of the plurality of image forming apparatuses furthercomprises a detector unit that detects a third image forming apparatusthat is disconnected from the first communication line, and the storagecontroller deletes from the first storage unit the storage informationindicating the storage location of the third image forming apparatusthat is detected by the detector unit.
 14. The plurality of imageforming apparatuses according to claim 13, wherein each of the pluralityof the image forming apparatuses further comprises: a second storageunit that stores the input identification information and a history ofthe storage location associated with the identification information, thestorage location from which the retrieval unit retrieves the image datawhen the identification information is inputted; and a calculator unitthat, when the identification is inputted by the user, calculates aretrieval frequency of retrieving the image data from each of thestorage locations in accordance with the history of the storage locationassociated with the identification information and stored on the secondstorage unit, wherein the retrieval unit accesses the storage locationsin the order of from the high to the low retrieval frequency calculatedby the calculator unit.
 15. The plurality of image forming apparatusesaccording to claim 13, wherein each of the plurality of the imageforming apparatuses comprises a display controller, wherein when theretrieval unit retrieves first image data from an internal storagelocation within the image forming apparatus hosting the retrieval unitand second image data from an external storage location within anotherimage forming apparatus, the display controller causes identificationinformation identifying the first image data to be displayed at apredetermined position on a display unit, and causes identificationinformation identifying the second image data to be displayed at aposition other than the predetermined position on the display unit, andwhen image data is selected from the retrieved image data by the user inaccordance with the identification information displayed on the displayunit, the image forming unit forms an image corresponding to theselected image data.
 16. A non-transitory computer readable mediumstoring a program causing a computer to execute a process for forming animage, the computer including a first storage unit storing storageinformation indicating a plurality of storage locations, the processcomprising: connecting a plurality of image forming apparatuses via afirst communication line, each of the plurality of the image formingapparatuses comprising a storage controller that retrieves, from asecond image forming apparatus which is newly connected to the firstcommunication line, storage information indicating a storage location ofthe second image forming apparatus when the second image formingapparatus is newly connected to the first communication line, and causesthe first storage unit to store the retrieved storage information,storing identification information and image data with theidentification information associated with each other when theidentification information identifying a user and the image data arereceived from a transmitter apparatus; accessing the plurality ofstorage locations indicated by the storage information stored on thefirst storage unit and retrieving the image data from the storagelocation when the identification information is inputted by the user;and forming an image corresponding to the retrieved image data, whereineach of the plurality of image forming apparatuses further comprises adetector unit capable of detecting a third image forming apparatus thatis disconnected from the first communication line, and wherein thestorage controller deletes from the first storage unit the storageinformation indicating the storage location of the third image formingapparatus that is detected by the detector unit.
 17. The non-transitorycomputer readable medium storing a program causing a computer to executea process for forming an image according to claim 16, wherein each ofthe plurality of the image forming apparatuses further comprises: asecond storage unit that stores the input identification information anda history of the storage location associated with the identificationinformation, the storage location from which a retrieval unit retrievesthe image data when the identification information is inputted; and acalculator unit that, when the identification is inputted by the user,calculates a retrieval frequency of retrieving the image data from eachof the storage locations in accordance with the history of the storagelocation associated with the identification information and stored onthe second storage unit, wherein the retrieval unit accesses the storagelocations in the order of from the high to the low retrieval frequencycalculated by the calculator unit.
 18. The non-transitory computerreadable medium storing a program causing a computer to execute aprocess for forming an image according to claim 16, wherein each of theplurality of the image forming apparatuses further comprises a displaycontroller, wherein when the retrieval unit retrieves first image datafrom an internal storage location within the image forming apparatushosting the retrieval unit and second image data from an externalstorage location within another image forming apparatus, the displaycontroller causes identification information identifying the first imagedata to be displayed at a predetermined position on a display unit, andcauses identification information identifying the second image data tobe displayed at a position other than the predetermined position on thedisplay unit, and when image data is selected from the retrieved imagedata by the user in accordance with the identification informationdisplayed on the display unit, the image forming unit forms an imagecorresponding to the selected image data.